Ltjdwig limpach



UNITED STATES PATENT FFICE.

LUDWIG LIMPACH, OF. BERLIN, GERMANY, ASSIGNOR TO LUDWIG FRIEDRICH RIEDEL, OF SAME PLACE.

PROCESS OF MAKING SALlCYLO-ACETIC ACID.

SPECIFICATION forming part of Letters Patent No. 611,014, dated September 20, 1898. Application filed December 1, 1897. Serial No. 660,428. (No specimens.) Patented in Germany June 14, 1896, No. 93,110.

To all whom it may concern.-

I have found that salicylo-acetic acid 1.2

simply and in theoretical quantity by heating the sodium salt of the 'salicylamid OONHQ o .n

ONa

then saponifying the group OONH by heating with soda solution. The reaction takes place as follows:

own on /C i ONa may be obtained very with monochloracetates and +NaOl.

ooNH, o,n, +NaO.H:

OCH .GOONa COONa o,r-I, +NH3. OOH .COONa Example: Thirteen parts of salicylamid, 4

eight parts of caustic soda, and 9.5 parts of chloracetic acid are dissolved in water, and the solution is caused to evaporate by heat until it begins to deposit crystals. After this the liquid is boiled, with the aid of a reflux cooler, until it no longer has an alkaline re action. From this solution the amid oi salicylo-acetic acid is precipitated by means of hydrochloric acid, and saponification is produced in the usual manner by boiling with alkali.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-

The process for the manufacture of salicyloacetic acid which consists in causing monochloracetates to act on salts of salicylamid, and saponifying the product thus obtained, substantially as described.

In testimonywhereof I have hereunto set my hand in the presence of two subscribing witnesses.

LUDWIG LIMPAOI-I. In presence of MARC FUoHs, Lnnwre WENeHorrER. 

